#include "glsl/GrGLSLUniformHandler.h"
#include "../private/GrGLSL.h"
+/*
+ * Filter weights come from Don Mitchell & Arun Netravali's 'Reconstruction Filters in Computer
+ * Graphics', ACM SIGGRAPH Computer Graphics 22, 4 (Aug. 1988).
+ * ACM DL: http://dl.acm.org/citation.cfm?id=378514
+ * Free : http://www.cs.utexas.edu/users/fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
+ *
+ * The authors define a family of cubic filters with two free parameters (B and C):
+ *
+ * { (12 - 9B - 6C)|x|^3 + (-18 + 12B + 6C)|x|^2 + (6 - 2B) if |x| < 1
+ * k(x) = 1/6 { (-B - 6C)|x|^3 + (6B + 30C)|x|^2 + (-12B - 48C)|x| + (8B + 24C) if 1 <= |x| < 2
+ * { 0 otherwise
+ *
+ * Various well-known cubic splines can be generated, and the authors select (1/3, 1/3) as their
+ * favorite overall spline - this is now commonly known as the Mitchell filter, and is the source
+ * of the specific weights below.
+ *
+ * These weights are in column-major order (ie this matrix is transposed from what you'd expect),
+ * so we can upload them directly via setMatrix4f.
+ */
+static constexpr float kMitchellCoefficients[16] = {
+ 1.0f / 18.0f, 16.0f / 18.0f, 1.0f / 18.0f, 0.0f / 18.0f,
+ -9.0f / 18.0f, 0.0f / 18.0f, 9.0f / 18.0f, 0.0f / 18.0f,
+ 15.0f / 18.0f, -36.0f / 18.0f, 27.0f / 18.0f, -6.0f / 18.0f,
+ -7.0f / 18.0f, 21.0f / 18.0f, -21.0f / 18.0f, 7.0f / 18.0f,
+};
+
class GrGLBicubicEffect : public GrGLSLFragmentProcessor {
public:
void emitCode(EmitArgs&) override;
private:
typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;
+ UniformHandle fCoefficientsUni;
UniformHandle fImageIncrementUni;
UniformHandle fColorSpaceXformUni;
GrTextureDomain::GLDomain fDomain;
const GrBicubicEffect& bicubicEffect = args.fFp.cast<GrBicubicEffect>();
GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
+ fCoefficientsUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
+ kMat44f_GrSLType, kDefault_GrSLPrecision,
+ "Coefficients");
fImageIncrementUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision,
"ImageIncrement");
const char* imgInc = uniformHandler->getUniformCStr(fImageIncrementUni);
+ const char* coeff = uniformHandler->getUniformCStr(fCoefficientsUni);
GrGLSLColorSpaceXformHelper colorSpaceHelper(uniformHandler, bicubicEffect.colorSpaceXform(),
&fColorSpaceXformUni);
+ SkString cubicBlendName;
+
+ static const GrShaderVar gCubicBlendArgs[] = {
+ GrShaderVar("coefficients", kMat44f_GrSLType),
+ GrShaderVar("t", kFloat_GrSLType),
+ GrShaderVar("c0", kVec4f_GrSLType),
+ GrShaderVar("c1", kVec4f_GrSLType),
+ GrShaderVar("c2", kVec4f_GrSLType),
+ GrShaderVar("c3", kVec4f_GrSLType),
+ };
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
-
- /*
- * Filter weights come from Don Mitchell & Arun Netravali's 'Reconstruction Filters in Computer
- * Graphics', ACM SIGGRAPH Computer Graphics 22, 4 (Aug. 1988).
- * ACM DL: http://dl.acm.org/citation.cfm?id=378514
- * Free : http://www.cs.utexas.edu/users/fussell/courses/cs384g/lectures/mitchell/Mitchell.pdf
- *
- * The authors define a family of cubic filters with two free parameters (B and C):
- *
- * { (12 - 9B - 6C)|x|^3 + (-18 + 12B + 6C)|x|^2 + (6 - 2B) if |x| < 1
- * k(x) = 1/6 { (-B - 6C)|x|^3 + (6B + 30C)|x|^2 + (-12B - 48C)|x| + (8B + 24C) if 1 <= |x| < 2
- * { 0 otherwise
- *
- * Various well-known cubic splines can be generated, and the authors select (1/3, 1/3) as their
- * favorite overall spline - this is now commonly known as the Mitchell filter, and is the
- * source of the specific weights below.
- *
- * This is GLSL, so the matrix is column-major (transposed from standard matrix notation).
- */
- fragBuilder->codeAppend("mat4 kMitchellCoefficients = mat4("
- " 1.0 / 18.0, 16.0 / 18.0, 1.0 / 18.0, 0.0 / 18.0,"
- "-9.0 / 18.0, 0.0 / 18.0, 9.0 / 18.0, 0.0 / 18.0,"
- "15.0 / 18.0, -36.0 / 18.0, 27.0 / 18.0, -6.0 / 18.0,"
- "-7.0 / 18.0, 21.0 / 18.0, -21.0 / 18.0, 7.0 / 18.0);");
- fragBuilder->codeAppendf("vec2 coord = %s - %s * vec2(0.5);", coords2D.c_str(), imgInc);
+ fragBuilder->emitFunction(kVec4f_GrSLType,
+ "cubicBlend",
+ SK_ARRAY_COUNT(gCubicBlendArgs),
+ gCubicBlendArgs,
+ "\tvec4 ts = vec4(1.0, t, t * t, t * t * t);\n"
+ "\tvec4 c = coefficients * ts;\n"
+ "\treturn c.x * c0 + c.y * c1 + c.z * c2 + c.w * c3;\n",
+ &cubicBlendName);
+ fragBuilder->codeAppendf("\tvec2 coord = %s - %s * vec2(0.5);\n", coords2D.c_str(), imgInc);
// We unnormalize the coord in order to determine our fractional offset (f) within the texel
// We then snap coord to a texel center and renormalize. The snap prevents cases where the
// starting coords are near a texel boundary and accumulations of imgInc would cause us to skip/
// double hit a texel.
- fragBuilder->codeAppendf("coord /= %s;", imgInc);
- fragBuilder->codeAppend("vec2 f = fract(coord);");
- fragBuilder->codeAppendf("coord = (coord - f + vec2(0.5)) * %s;", imgInc);
- fragBuilder->codeAppend("vec4 wx = kMitchellCoefficients * vec4(1.0, f.x, f.x * f.x, f.x * f.x * f.x);");
- fragBuilder->codeAppend("vec4 wy = kMitchellCoefficients * vec4(1.0, f.y, f.y * f.y, f.y * f.y * f.y);");
- fragBuilder->codeAppend("vec4 rowColors[4];");
+ fragBuilder->codeAppendf("\tcoord /= %s;\n", imgInc);
+ fragBuilder->codeAppend("\tvec2 f = fract(coord);\n");
+ fragBuilder->codeAppendf("\tcoord = (coord - f + vec2(0.5)) * %s;\n", imgInc);
+ fragBuilder->codeAppend("\tvec4 rowColors[4];\n");
for (int y = 0; y < 4; ++y) {
for (int x = 0; x < 4; ++x) {
SkString coord;
args.fTexSamplers[0]);
}
fragBuilder->codeAppendf(
- "vec4 s%d = wx.x * rowColors[0] + wx.y * rowColors[1] + wx.z * rowColors[2] + wx.w * rowColors[3];",
- y);
+ "\tvec4 s%d = %s(%s, f.x, rowColors[0], rowColors[1], rowColors[2], rowColors[3]);\n",
+ y, cubicBlendName.c_str(), coeff);
}
- SkString bicubicColor("(wy.x * s0 + wy.y * s1 + wy.z * s2 + wy.w * s3)");
+ SkString bicubicColor;
+ bicubicColor.printf("%s(%s, f.y, s0, s1, s2, s3)", cubicBlendName.c_str(), coeff);
if (colorSpaceHelper.getXformMatrix()) {
SkString xformedColor;
fragBuilder->appendColorGamutXform(&xformedColor, bicubicColor.c_str(), &colorSpaceHelper);
bicubicColor.swap(xformedColor);
}
- fragBuilder->codeAppendf("%s = %s;",
+ fragBuilder->codeAppendf("\t%s = %s;\n",
args.fOutputColor, (GrGLSLExpr4(bicubicColor.c_str()) *
GrGLSLExpr4(args.fInputColor)).c_str());
}
imageIncrement[0] = 1.0f / texture->width();
imageIncrement[1] = 1.0f / texture->height();
pdman.set2fv(fImageIncrementUni, 1, imageIncrement);
+ pdman.setMatrix4f(fCoefficientsUni, kMitchellCoefficients);
fDomain.setData(pdman, bicubicEffect.domain(), texture->origin());
if (SkToBool(bicubicEffect.colorSpaceXform())) {
pdman.setSkMatrix44(fColorSpaceXformUni, bicubicEffect.colorSpaceXform()->srcToDst());
projects / platform / upstream / libSkiaSharp.git / commitdiff